That was 2 parts white whine vinegar to 1 part hydrogen peroxide.
I believe the article was posted by a beer brewer during a discussion about brass parts.
Here is one of the links I could find on it.
It would be hard to find because I think it was buried in one of the big ole microcoil threads.
From the article:
Because 98% Acetic Acid and 30% Hydrogen Peroxide are not available to the
average brewer, the experiment was repeated using the concentrations
available in the supermarket. These are 5% Acetic Acid (White Distilled
Vinegar) and 3% Hydrogen Peroxide. Due to the difference in concentration,
the relative concentration ratio is changed. For the household variety
concentrations,
a 2-to-1 volume ratio of Acetic Acid to H2O2 is needed.